An infrared receiver is a fundamental device for realizing the remote control function of household electrical appliances, but the normal operation of the infrared receiver is influenced by external electromagnetic interference due to its high internal gain. To overcome the adverse influence produced by the electromagnetic interference, it is necessary to provide an electromagnetic shielding device inside the infrared receiver. The present inventor has conducted a long-term research and experiment on the above issue, and has designed and proposed a novel technical solution. Based on this technical solution, the present inventor has filed a patent application in early 2003, which was granted on Apr. 7, 2004 under Patent No. ZL03211316.1. The present application is made on the optimization and improvement of the above inventive patent, and is more reasonable in design, is easy to manufacture, and has higher engineering operability.